n-Type thermoelectric metal chalcogenide (Ag,Pb,Bi)(S,Se,Te) designed by multi-site-type high-entropy alloying

Abstract

A metal chalcogenide (Ag,Pb,Bi)(S,Se,Te) with an NaCl-type structure was designed by multi-site-type high-entropy alloying (MST-HEA), and the thermoelectric properties were investigated. In this material, both cation and anion sites were alloyed and thus its total entropy of mixing ΔS_mix (total) achieved 2.00R (R: gas constant). It was found that present sample is an n-type semiconductor with ultra-low lattice thermal conductivity (κ_L) of 0.62 Wm⁻¹K⁻¹ at room temperature and 0.46 Wm⁻¹K⁻¹ at T = 723 K. Very low κ_L and good power factor resulted in figure of merit of 0.54 at T = 723 K.

IMPACT STATEMENT

We report on the material design synthesis and thermoelectric properties on new high-entropy alloy-type compound with an NaCl-type structure (Ag,Pb,Bi)(S,Se,Te)

KEYWORDS:

• High-entropy-alloy
• material design
• new thermoelectric material
• NaCl-type structure

Acknowledgements

The authors thank T. Mitobe and K. Morino for supports in experiments.

Disclosure statement

Experimental data are available via reasonable requests to the corresponding author. No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by JST-CREST (JPMJCR20Q4) and the Tokyo Metropolitan Government Advanced Research (H31-1).